A DAMNING report has revealed the true scale of the police blunders which allowed a Plymouth rapist to evade justice for more than two decades

The conclusions of the Independent Police Complaints Commission (IPCC) about errors made in using DNA evidence by forces nationwide prompted one former detective to say thousands of sex offenders who should be behind bars could be walking Britain's streets. Stewart Butler – a retired Detective Sergeant who headed the original Plymouth rape inquiry – fears yesterday's IPCC report into the way Devon and Cornwall Police handled the case could show every force in the country may have made the same mistakes.

The Herald reported last month how Shaun Harrison was jailed for the rape in 1989 of a teenage girl.

Harrison, 46, of North Prospect, was jailed for eight years last month after being found guilty of two rapes and two indecent assaults. The first was of the teenage girl in a Plymouth car park, the other a woman outside a city nightclub in 1995.

DNA evidence was collected but the Devon and Cornwall force did not update the police database so when Harrison's DNA was taken after a separate offence several years later the two were not matched. He was only caught after a bizarre false confession by another man two years ago which prompted detectives to re-open the case.

The IPCC found Plymouth police failed to act on repeated requests to "upgrade" DNA evidence.

The IPCC found the force had not instructed the Forensic Science Service (FSS) to load the original DNA onto the database – established in 1995 – despite repeatedly being advised to do so.

Shockingly, when police finally upgraded forensic samples last year, they found three further matches – from 1989, 1990 and 1993. As a result, more rapists were identified and jailed.

The IPCC said all police forces were asked by the FSS in 1996 to update older versions of DNA samples to a newer version.

Two years later the FSS contacted Devon and Cornwall Police highlighting 10 serious sex cases – including the 1989 Harrison rape – held on the older database that were "worthy of an upgrade" onto the new national database.

The force chose two of the 10 – not including Harrison's rape.

The IPCC said Devon and Cornwall Police had a "number of opportunities" to review the case but had "failed".

The IPCC noted how the Harrison case acted as a "trigger" for the force to "conduct a comprehensive review of all their undetected serious sex crimes".

Deputy IPCC chair Deborah Glass said: "Devon and Cornwall Police missed opportunities over the years to review this case.

"This meant that Harrison's and other DNA samples were not upgraded in line with forensic advancements."

Now city MP Oliver Colvile and North Devon MP Nick Harvey have called upon the Home Secretary and the Association of Chief Police Officers (ACPO) to demand all police forces ensure they have not made similar errors.

Mr Colvile said he would table Parliamentary questions over the fiasco.

Mr Butler added: "It's a major, major failure in the system. If other police forces have made the same mistakes then there will be people walking around the streets, serious offenders, who've not been identified because of this mistake.

"There could be hundreds of cases out there, if not thousands around the country."

But, in a statement, a spokesman said: "We welcome and fully accept the findings of the report, much of which relate to historic practices.

"We have already adopted much of the learning contained within the IPCC report.

"This investigation has highlighted a potential national issue around how historic DNA should be treated.

"However, DNA technology has progressed significantly since 1989 and the way police investigate such offences is now very different.

"Devon and Cornwall Police have proactively sought to identify any such cases and have currently found three related to historic, undeveloped DNA hits.

"All of these cases have been voluntarily referred to the IPCC and have all now resulted in substantial prison sentences for offenders."

An ACPO spokeswoman added: "ACPO will work with the IPCC in relation to any lessons which may need to be shared with the wider service as a consequence of their investigation into this particular case."